The present invention relates to a hologram laminate and a hologram label that are suitable for certification and forgery preventing purposes.
Holograms allow information to be recorded on the surface of a hologram layer or in the direction of the thickness of a hologram layer and also permit three-dimensional image recording and reconstruction. Further, holographic images have an appearance that cannot readily be obtained by other image forming means because they are represented by the interference color of light. Although the method of producing holograms is per se known, it is difficult to forge holograms because the production thereof requires a precise operation using optical equipment. Accordingly, holograms are used as labels for certifying that labeled articles are authentic, and also used to prevent forgery of ID cards, bank cards, etc.
Various holograms are known, for example, a relief hologram in which information is recorded on the surface of a hologram layer, and a volume hologram in which information is recorded in the direction of the thickness of a hologram layer. When such a hologram is bonded to an adherend by using a pressure-sensitive adhesive, the hologram layer is readily separable due to the difference in material between the hologram layer and the adherend and hence replaceable with another. Therefore, it is necessary to make it impossible to replace the hologram layer with another when the hologram is used as a label for certification.
Under these circumstances, Japanese Patent Application Unexamined Publication (KOKAI) No. 2000-194265 discloses a hologram laminate comprising an adherend, a hologram layer and a surface protective film. In the hologram laminate, the surface protective film is provided with a release pattern, and the hologram layer is laminated over the release pattern fabricated surface of the surface protective film with a colored pressure-sensitive adhesive layer interposed therebetween. It is stated in the publication that when the hologram layer is separated, the colored layer is left on the adherend in a pattern corresponding to the release pattern, thereby preventing forgery. In the hologram laminate disclosed in the above-described publication, however, the bond strength of the colored pressure-sensitive adhesive layer is so high that the pattern showing the separation of the hologram is unclear. Accordingly, the conventional hologram laminate is inadequate for certification purposes. When the hologram laminate is used as a seal for certification, it is demanded that a pattern showing traces of separation of the hologram should be left even more clearly on both the adherend and the hologram label.
The present invention relates to a hologram laminate that allows traces of separation of the hologram to be clearly left on both the adherend and the hologram label and hence makes it possible to prevent reuse of the hologram. The present invention also relates to a hologram label used for the fabrication of the hologram laminate.
The present invention provides a hologram laminate having a metal thin-film layer, a release pattern, a transparent film, a hologram layer and a surface protective layer laminated on an adherend in the order mentioned. The hologram laminate is separable between the adherend and the transparent film. When the hologram is separated, the metal thin-film layer is left on the adherend in a pattern corresponding to the release pattern.
In addition, the present invention provides a hologram label having a metal thin-film layer, a release pattern, a transparent film, a hologram layer and a surface protective layer laminated on a release sheet in the order mentioned. The hologram label is separable between an adherend and the transparent film when it is stuck on the adherend at a surface thereof exposed by removal of the release sheet. When the hologram is separated, the metal thin-film layer is left on the adherend in a pattern corresponding to the release pattern.
The above-described metal thin-film layer may be a silver deposited layer.
The above-described surface protective layer may be a coating for surface protection.
The surface protective layer may be a film.
In the hologram laminate according to the present invention, when the hologram is separated, traces of the separation of the hologram are clearly left on the adherend. In addition, reuse of the separated hologram can be prevented. Accordingly, the hologram laminate is superior in forgery preventing properties and suitable for certification purposes. The hologram label according to the present invention allows a hologram laminate to be formed by sticking it on an adherend after removing the release sheet therefrom. Thus, it is possible to readily form a hologram laminate superior in forgery preventing properties and suitable for certification purposes.